Bone rasps are commonly used in orthopedic surgery, especially in surgery involving the phalangeal, metatarsal or metacarpal bones, as part of the process of bone fusion. Many orthopedic surgeries such as osteotomy and arthrodesis procedures involve the use of a bone rasp. Under certain circumstances, a type of device, such as an internal fixation pin (an intramedullary pin), is inserted into the ends of the opposed bones, bone portions or bone fragments as part of such procedures referred to as interphalangeal or metatarsophalangeal arthrodesis—arthrodesis being the surgical immobilization of a joint so that the bones can grow solidly together. Generally, once the fixation pin has been placed within the ends of adjacent bones, the pin cannot be redirected, i.e., its orientation cannot change; and the pin is often oblique to the adjacent end surface of one or both bones—the end surfaces of the bones defining the arthrodesis site and plane of fusion where the ends of the bones are adjoined. It is often the case that the bone surfaces at the ends of both bones are irregular and/or not congruent or located in parallel planes—a condition that hinders and often prevents the successful fusion of the bone surfaces so that the bones will not grow solidly together (non-union).
Therefore, bone reduction and remodeling must be carried out by the bone rasp upon the two opposed, irregular and non-planar bone surfaces, with one or both bone surfaces possibly being oblique to the axis of the internal fixation pin that joins and stabilizes the ends of the bones. However, conventional rasps have several critical shortcomings in so far as they do not allow for the simultaneous removal of bone from the bone surface on both sides of the intramedullary (internal fixation) pin during such procedures as interphalangeal or metatarsophalangeal arthrodesis. Moreover, a conventional bone rasp does not provide for a rapid, accurate and efficient method to address and overcome this surgical dilemma. This results in a notoriously high rate of non-union (the failure of the contiguous, end-to-end growth together of the bones at the end surfaces) in conventional end-to-end arthrodesis procedures, and improvement is desirable with the appropriate refinement of the instrumentation, i.e., an improved bone rasp. Improvements in the bone rasp should provide for a more accurate reduction—surgical bone remodeling—of the opposed end surfaces of the bones for achieving optimal congruity between the bone surfaces while maintaining bone stabilization and relative orientation via the in situ internal fixation pin. Also, the improved bone rasp should decrease the operative time and, thereby, the rate of non-union, that is the failure of the end surfaces of both bones to join and fuse in an end-to-end, parallel and contiguous configuration.
The prior art discloses a variety of orthopedic devices, rasps, and abraders for shaping and forming various bones and bone structures as part of various types of surgical procedures.
For example, the Rubin patent (U.S. Pat. No. 3,467,100) discloses a nasal osteotome that includes a handle from which two legs extend, one of which is pointed and the other having a plane end surface for striking with a hammer or other tool.
The Davison et al. patent (U.S. Pat. No. 4,625,725) discloses a surgical rasp for cosmetic or facial surgery and includes a handle and an insert with a geometric tooth pattern arranged thereon.
The Berry Jr. patent (U.S. Des. Pat. 304,372) discloses on ornamental design for a surgical bone rasp that includes a handle and an attached serrated portion.
The Hafeli patent (U.S. Pat. No. 5,006,121) discloses a bone broach that prepares a bone for an implant and includes a mandrel on which a plurality of broach plates are stacked with each plate having a peripheral region that defines a cutting edge for making the desired bone opening.
The Michelson patent (U.S. Des. Pat. 324,424) discloses an ornamental design for a spinal osteotome that includes a handle and a serrated portion attached thereto with the serrated portion having a plurality of spaced-apart apertures disposed along the body of the serrated portion.
The Koros et al. patent (U.S. Des. Pat. 338,528) discloses an ornamental design for a flexible hip prosthesis osteotome that includes a round handle from which a flat file-shaped portion projects in axial alignment with the handle.
The Waldman patent (U.S. Pat. No. 5,342,365) discloses a rasp for plastic and reconstructive surgery that includes a handle having an insert with teeth arranged on the insert in parallel rows relative to the longitudinal axis of the handle.
The Puddu patent (U.S. Pat. No. 5,620,448) discloses a bone plate system for performing tibial or femoral osteotomies and which includes a forked-wedge tool for opening a wedge in the bone and a set of bone plates for maintaining the wedge opening.
The Holko et al. patent (U.S. Pat. No. 5,707,276) discloses an abrader blade having an abrasive surface and a pair of opposed depth control wings for controlling the depth of the shape that is abraded into the hard object such as bone tissue.
The Grunig et al. patent (U.S. Pat. No. 6,120,508) discloses a rasp that includes a handle adapter to which is mounted an inner support unit. Mounted on the inner support unit is a toothed exterior envelope of metal or surgical steel and which can be discarded after use.
The Chappuis Patent Application (U.S. Publication No. US2002/0138078 A1) discloses a system and method for facilitating bone grafting and which includes a rasp, a sizer, a cutting guide, a measuring pan and a holding device.
Nonetheless, despite the ingenuity of the above systems, methods and devices, there remains a need for an orthopedic device that is capable of working around a fixation pin for rapid and optimal remodeling of the irregular end surfaces of two opposed bones stabilized by the fixation pin where the end surfaces of the bones are non-parallel and/or oblique to the axis of the fixation pin and that can simultaneously reduce and remodel bone located at end surfaces on either side of the fixation pin.